The show cited an unnamed source who said that investigators are probing whether the U.S. cyclist had ever obstructed justice or tampered with or intimidated witnesses—different charges than those previously considered a federal level.

U.S. Attorney Andre Birotte, who led a federal probe that was dropped last year, said Tuesday he had no plans to press charges despite Armstrong's recent doping admissions, but he did not definitively rule out such action.

Birotte's investigation was centered on doping, fraud, and conspiracy, and Armstrong's denials of such crimes when he was the lead rider in the successful government-funded U.S. Postal Service Team in the late 1990s and early 2000s.

"Obviously we've been well aware of the statements that have been made by Mr. Armstrong and other media reports," Birotte said, referring to Armstrong's doping confession to Oprah Winfrey last month.

"That has not changed my view at this time. Obviously we'll consider—we'll continue to look at the situation," Birotte told reporters in Washington.

The ABC News source explained, "Birotte does not speak for the federal government as a whole. Agents are actively investigating Armstrong for obstruction, witness tampering, and intimidation."

Armstrong also faces other legal battles after being stripped last year of his record seven Tour de France titles.

Dallas insurance company SCA Promotions has already demanded the return of $12 million in bonuses it paid the Texan for winning five consecutive Tours.

SCA attorney Jeff Dorough told the AFP that the firm expected to file a lawsuit against the 41-year-old Armstrong as early as Wednesday.